Method of and apparatus for forming webs from paper-pulp.



A. J. HAUG. METHOD OF AND APPARATUS FOR FORMING WEBS FROM PAPER PULP. APPLICATION FILED :um 21. 2915.

$13,998.. Patented m. 14, 1915.

hi TC.

ANTON JOSEPH HAUG, OF NASHUA, NEW HAMPSHIRE, ASSIGNOR '10 IMPROVED PAPER MACHINERY COMPANY, OF NASHUA,

MAINE.

NEW HAMPSHIRE, A CORPORATION OF Specification of Letters Patent.

Patented Dec. ML, 1915.

Application filed June 21, 1915. Serial No. 35,228.

To all whom it may concern:

Be it known that I, ANTON J. JZLAUG, a citizen of the United States, and a resident of Nashua, county of Hillsborough State of New Hampshire, (whose post-o ce address is care of Improved Paper Machinery Company, Nashua, New Hampshire,) have invented an Improvement in Methods of and Apparatus for Forming Webs from Paper- Pulp, of which the following description, in connection with the accompanying drawings, is a specification, like characters onthe draw ings representing like parts.

This invention relates to methods ofand apparatus for forming webs from pulp stock used in paper manufacture and more particularly to the formation of such a web by means of a couch roll operating in conjunction with a cylinder mold or drum.

For purposes of illustration the invention is shown herein as applied to a Decker, but the same has application to other types of pulp handling machines where similar conditions pertain.

The invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings: Figure 1 is an end elevation showing one form of the invention applied to a cylinder machine, herein a Decker; Fig. 2 is a plan view of a part of the machine shown in Fig. 1,; and Fig. 3 is a front elevation, in partial section, showing parts of the driving mechanism illustrated in Figs. 1 and 2.

Referring to the drawings and to the illustrative embodiment of the invention, the Decker is provided with the casing 1 in which is journaled for rotary movement the screen drum 2, which is of any usual or or dinary construction. The casing forms a tank for pulp stock admitted thereto through any suitable inlet, in which stock the screen drum is partly immersed, whereby, as the drum rotates, the pulp is withdrawn from the tank in the form of a layer or web on the screen and removed therefrom by the couch roll 3 which rotates in contact with the drum. From the couch roll the pulp layer is taken by the press roll a and removed therefrom by the doctor 5, all of usual and common construction.

The couch roll is kept in contact with the screen drum, as is usual in this class of devices, by being journaled in a pair of arms, one of which is indicated at 6, the arms being pivoted on, the machine frame and connected at the opposite end to devices 6 which give the desired pressure of the couch roll against the drum subject to adjustment through the adjusting wheel 6.

To impart rotative movement to the screen drum the shaft of the latter is provided with the large driving gear 7 meshing with the driving pinion 8, the latter on the main driving shaft 9 to which turning movement is imparted from any convenientsource of driving power.

\Vhere the couch roll has heretofore been driven by frictional contact with the surface of the screen drum, unsatisfactory results have been had These have been due to several causes. Among them is the'injury to the screen drum itself. If the pressure of the couch roll against the screen is sufficient to givethe required frictional driving movement, continued operation under these conditions tends to injure the surface of the screen. Furthermore, it has been found that the couch roll acts more efiectively to take up stock from the screen at a relatively low pressure of contact than at an excessive pressure. In fact, different couch rolls, that is to say rolls of different construction and material or different depth of facing or different character of surfacing, require difierent pressures for the best results. When the couch roll is driven frictionally from the screen drum, the right pressure for most efiective results is never had and such pressure is almost invariably much too great. 0n the other hand, it is necessary that the couch roll should be so driven that the surface speed is the same as the surface speed of the screen and neither greater nor less than that of the latter.

My method contemplates the driving of the couch roll by forces which are independent of the frictional contact between the roll and the cylinder while at the same time maintaining the surface speed of the roll and cylinder the same. To accomplish this it is necessary to make provision for the gradual but material changes in diameter which the couch roll will undergo through contlnued use. A covering of some soft material such as felt is usually employed for the couch roll. Whether this covering be thick or thin it is subject to wear through continued use, so that the diameter of the roll gradually diminishes. The body of the roll is often constructed of wood and this undergoes shrinkage at one time and expansion at another. Where the couch roll is driven by means independent of the frictional contact with the cylinder it is therefore necessary to provide for a finely graduated control in the speed of the couch roll so as to ofiset the gradual changes in the diameter of the roll and so that it may at all times be caused to have the same surface speed as the cylinder.

In the illustrated embodiment of the invention this object is effected by providing a mechanical drive for the couch roll which is connected to the main driving shaft 9 so that the couch roll is driven at a rate strictly proportional to the movement of the screen drum. At the same time suitable devices are provided for adjusting the transmission mechanism between the driving shaft and couch roll so that the rotative speed of the latter may be regulated by finely graduated amounts and the couch roll at all times given the same surface speed as the cylinder. Referring to the details of the illustrated machine, this purpose is effected by providing the couch roll shaft 10 with a driving pulley 11, which latter is driven through the belt 12 from a driving pulley 13. The latter is rotated by the attached sprocket wheel 14 connected through the driving chain 15 to the driving sprocket wheel 16 mounted the main driving shaft 9 of the machine. This provides a mechanical drive for the couch roll shaft direct from the main driving shaft, which latter also drives directly the screen drum 2.

-ln order to adjust the speed of the couch roll the driving pulley 11 isexpansihle in form, comprising seginentai rim sections as indicated which may be moved radially outward or inward. by eans of the hand wheel 17. Such types of ex v 'nsible driving pulleys are Well-known in the art and require no further description. By this means the efi'ective diameter of the driving pulley 11 may be increased or diminished and the speed of the couch roll varied within re esonable limits by finely graduated amounts.

Suitable means are provided for automatically taking up or letting out the slack in the driving belt 12 as the diameter of the expansible pulley is increased or decreased. For this purpose an idle pulley or roller 18 is provided which engages with the under-- side of the lower run of the belt 12.- This pulley acts as a belt tightener, being carried by the pair of arms 19 pivoted at 20 on the upright supporting members 21 and pressed 7 upwardly by the weight 22 which is carried by rearwardly projecting portions 23 of the arms 19.

To maintain the driving chain 15 tight, the driving sprocket 14 and driving-pulley 13 are mounted on journals 24 sustained by the frame 25, which latter is pivoted at 26 on the'upright frame members 21, the rearwardly projecting portion of the frame 25 being weighted at 27 so that the sprocket wheel 14 has a tendency to swing up about the pivot 26 and keep the driving chain tight.

The couch roll being driven by the above described means, a surface speed may be had at all times equal to that of the screen drum and without the excessive pressure required by frictional driving. This results in materially lengthening the life and'durability of the screen while the pressure of the couch roll against the screen may be adjusted to exactly that point required for the most effective action on the stock and freev from any considerations of what pressure is required for drivin the roll. By theme-ans described, the sur ace speed of the couch roll may be made to conform exactly to that of the screen drum irrespective of any gradualchanges in diameter of the couch roll.

While I have herein shown and described for purposes of illustration one specific embodiment of the invention and one preferred mode of carrying out my improved method, it is to be understood that the same may be varied within wide limits without departing from the spirit of the invention.

Claims:

1. In a paper making machine, the combination with'a cylinder, of a couch roll in contact therewith, driving means for turn ing the cylinder, driving means for the couch roll to drive the latter independent of its frictional contact with the cylinder, and speed varying means accurately to adjust the surface speed of the couch roll at all times to equal that the cylinder.

2 In a paper making machine, the combination with a screen drum of a couch roll in contact therewith, a driving member to i turn the drum, and driving mechanism for the couch roll connected to the said driving member, said mechanism including variable speed means to accurately adjust the surface speed of the couch roll te equal that of the screen. drum irrespective of variations in diameter of the couch roll.

3. In a paper making machine, the conr 'iunation with a drum of a couch rcil, a driving member for the screen drum and driving mechanism for the couch roll also connected. to the said driving member to turn the couch irrespective of frictional contact with the screen drum, said driving mechanism including an expansihle lltl messes pulley, a driving belt therefor and an automatic belt tightener.

4. lhe method of forming a sheet of pulp which consists in rotating a cylindrical screen to cause its surface to enter and withdraw from the pulp, removing the sheet from the screen by the contact therewith of a couch roll, rotating the couch roll independently of its frictional contact with the 10 screen and maintaining the rotation of the couch roll at the same rate of surface speed as that of the screen.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

ANTON JOSEPH HAUG.

Witnesses WILLIAM MARDEN, FRED CLIFFoRD. 

